Phylogenetic relationships of some wild wheat species based on the internal transcribed spacer sequences of nrDNA

The cultivated wheat, Triticum aestivum, is one of the most important staple crops in the world. There has been great interest in the determination of ancestral diploid genome donors of T. aestivum - an allohexaploid, because of agronomic significance. Southeastern Turkey in Karacadag District of the Diyarbakir province, exhibits great genetic diversity in terms of Triticeae family plants, where wheat was originally domesticated. In order to better understand the phyletical relationships between T. aestivum and its possible ancestral genome donors, tissue samples were collected from 38 individuals belonging to four species of Triticum and two subspecies of Aegilops speltoides, distributed throughout the above-mentioned geographical area. The ITS1, ITS2 and 5.8S rDNA repeat segments from these plants were sequenced and the nucleotide sequences were phyletically analysed. The results postulated that Triticum monococcum var. boeoticum is likely to be an a genome donor of both, Triticum dicoccoides (AABB) and Triticum aestivum (AABBDD). The results further support Ae. speltoides as a possible B genome source.